import java.util.LinkedList;
import java.util.Queue;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: mirac
 * Date: 2025-08-21
 * Time: 17:24
 */
public class MyBinaryTree {

    //生成一个默认二叉树
    public TreeNode func() {
        TreeNode A = new TreeNode('A');
        TreeNode B = new TreeNode('B');
        TreeNode C = new TreeNode('C');
        TreeNode D = new TreeNode('D');
        TreeNode E = new TreeNode('E');
        TreeNode F = new TreeNode('F');
        TreeNode G = new TreeNode('G');
        TreeNode H = new TreeNode('H');

        A.left = B;
        A.right = C;
        B.left = D;
        B.right = E;
        E.right = H;
        C.left = F;
        C.right = G;
        return A;
    }

    // 前序遍历
    public void preOrder(TreeNode root) {
        if (root == null) return;
        System.out.print(root.val + " ");
        preOrder(root.left);
        preOrder(root.right);
    }

    // 中序遍历
    public void inOrder(TreeNode root) {
        if (root == null) return;
        inOrder(root.left);
        System.out.print(root.val + " ");
        inOrder(root.right);
    }

    // 后序遍历
    public void postOrder(TreeNode root) {
        if (root == null) return;
        postOrder(root.left);
        postOrder(root.right);
        System.out.print(root.val + " ");
    }

    // 获取树中节点的个数
    public int nodeSize;
    public void size(TreeNode root) {
        if (root == null) return;
        this.nodeSize++;
        size(root.left);
        size(root.right);
    }
    // 获取树中节点的个数_子问题思路
    public int size1(TreeNode root) {
        if (root == null) return 0;

        int leftSize = size1(root.left);
        int rightSize = size1(root.right);

        return 1 + leftSize + rightSize;
    }

    // 获取叶子节点的个数
    public int leafSize;
    public void getLeafNodeCount(TreeNode root) {
        if (root == null) return;
        if (root.left == null && root.right== null) this.leafSize++;
        getLeafNodeCount(root.left);
        getLeafNodeCount(root.right);
    }
    // 获取叶子节点的个数_子问题思路
    public int getLeafNodeCount1(TreeNode root) {
        if (root == null) return 0;
        if (root.left == null && root.right == null) {
            return 1;
        }
        int leftSize = getLeafNodeCount1(root.left);
        int rightSize = getLeafNodeCount1(root.right);
        return leftSize + rightSize;
    }

    // 获取第K层节点的个数
    public int getKLevelNodeCount(TreeNode root,int k) {
        if (root == null) return 0;
        if (k == 1) return 1;

        return getKLevelNodeCount(root.left,k - 1)
                + getKLevelNodeCount(root.right,k - 1);
    }

    // 获取二叉树的高度
    public int getHeight(TreeNode root) {
        if (root == null) return 0;
        int leftHeight = getHeight(root.left);
        int rightHeight = getHeight(root.right);

        return leftHeight > rightHeight?leftHeight + 1:rightHeight + 1;
    }

    // 检测值为value的元素是否存在
    public TreeNode find(TreeNode root, char val) {
        if (root == null) return null;
        if (root.val == val) return root;
        TreeNode leftNode = find(root.left,val);
        if (leftNode != null) return leftNode;
        TreeNode rightNode = find(root.right,val);
        return rightNode;
    }

    //判断一棵树是否是平衡二叉树
    public boolean isBalanced(TreeNode root) {
        if(root == null) return true;
        int leftHeight = getHeight1(root.left);
        int rightHeight = getHeight1(root.right);
        return (Math.abs(leftHeight - rightHeight) <= 1)
                &&isBalanced(root.left)
                && isBalanced(root.right);
    }
    // 获取二叉树的高度
    public int getHeight1(TreeNode root) {
        if (root == null) return 0;
        int leftHeight = getHeight(root.left);
        int rightHeight = getHeight(root.right);

        return leftHeight > rightHeight?leftHeight + 1:rightHeight + 1;
    }

    //判断一棵树是否是平衡二叉树_方法二
    public boolean isBalanced2(TreeNode root) {
        if(root == null) return true;
        return getHeight2(root) >= 0;
    }
    // 获取二叉树的高度
    public int getHeight2(TreeNode root) {
        if (root == null) return 0;

        int leftHeight = getHeight2(root.left);
        if (leftHeight < 0) {
            return -1;
        }
        int rightHeight = getHeight2(root.right);
        if (rightHeight >= 0 && Math.abs(leftHeight - rightHeight) <= 1) {
            return leftHeight > rightHeight?leftHeight + 1:rightHeight + 1;
        }else {
            return -1;
        }
    }

    //层序遍历
    public void levelOrder(TreeNode root) {
        if(root == null) return;
        Queue<TreeNode> queue = new LinkedList<>();
        queue.offer(root);
        while (!queue.isEmpty()) {
            TreeNode cur = queue.poll();
            System.out.print(cur.val + " ");
            if (cur.left != null) {
                queue.offer(cur.left);
            }
            if (cur.right != null) {
                queue.offer(cur.right);
            }
        }
        System.out.println();
    }

    // 判断一棵树是不是完全二叉树
    public boolean isCompleteTree(TreeNode root) {
        if(root == null) return true;
        Queue<TreeNode> queue = new LinkedList<>();
        queue.offer(root);
        while (!queue.isEmpty()) {
            TreeNode cur = queue.poll();
            if (cur != null) {
                queue.offer(cur.left);
                queue.offer(cur.right);
            }else {
                break;
            }
        }
        while (!queue.isEmpty()) {
            TreeNode cur = queue.peek();
            if (cur != null) {
                return false;
            }
            queue.poll();
        }
        return true;
    }
}
